"that you may approve the things that are excellent, that you may be sincere and without offense till the day of Christ"
The NIV inches us closer:
"so that you may be able to discern what is best and may be pure and blameless for the day of Christ"-NIV
But when we look at literal translations we see a clearer picture of the charge:
"for your proving the things that differ, that ye may be pure and offenceless -- to a day of Christ"-Young's Literal
"To the end ye may be putting to the test the things that differ, in order that ye may be incorrupt and may give no occasion of stumbling, unto the day of Christ"
The KJV isn't horrible. We do need to look for the "excellent" thing. But, unfortunately, "dokimázō" translated "approve" is better understood as "testing" something. The word translated "excellent" is "diaphérō" which has the idea of "finding the better of what differs." Strong's concordance gives us this, in part:
"subjectively to “differ”, or (by implication) surpass: - be better"
So, yes, we are looking for what is "better," but we are testing those things that are different to get there. In many cases, we must do this that we may "walk worthy of the calling with which [we] were called." (Eph 4:1)
I must walk in the calling of my age. Adopting practices or doctrines from another age, even though they are holy and of God, may put me in the way of disobedience. So many churches walk in the ways of other ages and claim the promises of other people. They will find themselves wanting in the day of Christ's appearing.
We are called to test or prove the "things that differ." When we look at scripture, we see "things that differ." One of these things are the lists of the Tribes of Israel. Would that mean the Bible is in error? Actually, as with all the things the differ, the differing lists are consistent with the plan of God and reveal to us scriptural and prophetic truth.
Next time we will look at the differing lists of tribes. But for now, let's look at the context of Phil 1:10:
"For God is my witness, how I long for you all in the bowels of Jesus Christ,and this I pray, that your love yet more and more may abound in full knowledge, and all judgment, for your proving the things that differ, that ye may be pure and offenceless -- to a day of Christ"
-Phil 1:8-10 (Young's Literal)
Paul prays that they "may abound in full knowledge, and all judgment" and thus be able to successfully "prov[e] the things that differ."
Here we look to the NIV, as a paraphrased commentary:
"And this is my prayer: that your love may abound more and more in knowledge and depth of insight"
The perfect (mature) Christian works with the Word of Truth (2 Tim 2:15) and looks to God for "depth of insight" when he sees "things that differ."
"It is the glory of God to conceal a thing: but the honour of kings is to search out a matter."